When developing a new transportation system based on the current roadway and railway systems and incorporating the linear motor system into those, problems arise that require dealing with. These includes the driving force, support systems, guiding and steering, preventing lane deviation, merging and diverging, deceleration, and vehicle structure. The following defines those concerns.
In this invention, deviation is defined as a vehicle straying from the provided lane and losing it's power and control. This occurs when the vehicle exceeds the range provided for it within it's designated lane.
Also, within this invention, the term "vehicle" includes automobiles (cars, trucks, busses etc.), railroad cars, pallet vehicles, vehicles of new transportation system and so on. Customarily, in the automobile field, a vehicle is called an automobile or a car, and in railroad system, it is also called a car.
In this invention, the general term "vehicle" includes the whole scope of vehicles with the wheel supported system.
This pallet system is more understandable when the vehicle and the pallet are separated, even though pallet is connected to the vehicle. Hence, these are alluded to separately in this invention.
In this invention, pallet includes the vehicle that is able to mobile and it carries automobile or container after fixing it onto the pallet. This also includes the pallet which does not have wheels.
In this invention, lane means the road surface on which the vehicle moves.
In this invention, the mode-interchange means the place or facility where the vehicle or container is loaded and unloaded to and from the pallet where it is fixed and unfixed to the pallet. The mode of mobility and transportation is changed from an internal combustion engine to the pallet carrying system. Also, the mode interchange is the place where the vehicle, which has an ability of automated driving system, drags down the fin, which is described in detail later, the fin is then inserted into the ditch, which is also described later in the invention, to prevent the lateral deviation mechanically. The mode-interchange provides mechanical fail safe system to make fully automated driving possible, and it is installed to the entrance or exit of the new transportation/logistics system.
In this invention, wireless means any method not using a wire. Specifically, it includes not only electric waves, but also lights, rays, electromagnetic waves, infrared lights, ultra-violet lights, laser beams, supersonic waves and so on.
In this invention, guide means not only the guideway such as in railroads which control the wheels on the track, but also the autonomous steering along the roadway or driving lane. Thus, steering an automobile enables "curving" is in the definition of the guide or to guide using both the noun and verb forms of the word.
The current road-automobile system is comprised of the road which is linear in shape and provide the structure to support the automobile, and the automobile moves along the road.
The elementary mobility system of the automobile is comprised of three basic functions which are "forward progression", "direction change" and "deceleration". The "forward progression" is provided by the power generator which produces the driving force, "direction change" is performed by steering right and left, "deceleration" is generally made by breaking the wheel to slow or stop the vehicle.
Also, there are other movements such as vertical movement or pitching which is an important factor related to the comfort of the ride in the vehicle. ("Maneuverability and stability of automobile" author: Katsumi Kageyama, published by Sankaido, Feb. 10, 1992, p.1)
To power the vehicle, how most automobiles are driven by using combustion of fossil fuel. As a result, this method of generating power is not environmentally friendly. The current automobile has an intrinsic problem which is polluting atmosphere.
Most automobiles can produce speed of 180 to 200 km/h (most automobile's speedometer maximizes at about 180 km/h). The legal speed limit is generally regulated at about 100 km/h because automated driving system is not available and keep safety must be maintained by the driver. Therefore, this system of travel is, in a sense, defective because the automobiles cannot maximize their engine's output and travel at potential top speeds. Human error affects the road-highway system and forces the drivers to maintain relatively low speeds when in comparison to the rail or air system.
The automobile obtains it's power from the engine, the obtained power is then transferred to the wheel base through the crutch, transmission, propelling shaft and differential gears etc. Finally the tire revolves on the ground to utilize the driving power.
All of the power is not utilized while obtaining the driving force directly. This is because the vertical movement which is generated by the combustion of the fuel in the engine is converted to a rotational movement by the crank shaft. Secondly, the original rotation speed is changed, then the rotation power is transmitted to the propelling shaft. Thus rolls the wheel and provides the power to move the tire. In this manner, there are many transmitting and converting processes. Thus, it is easily suggested that the road-automobile transportation system is not efficient as long as the consumption of fossil fuel is concerned.
For example, according to "Energy Handbook for Transportation" which is published by the Department of Transportation of Japan, energy consumption of passenger automobiles is as large as five times that of a train when the train contains a regular number of passengers.
In the case of the automobile, the tire moves along the ground and produces friction from the ground to maintain a driving force. Thus, the driving force is affected by the condition of the ground. Because the climate or condition of the ground affects the efficiency of the consumption energy, design of the road becomes a critical and complicated issue.
For example, even if the same type of automobile is driven, each automobile's energy efficiency depends on the conditions of each wheel. The surface of the wheel can be new or old, slippery or wet, size and material of the tire and even the internal tire pressure all affect it's efficiency.
The affects by the road condition cannot be ignored. If the surface of road gets wet, the friction between tire and the road lessens. The same thing happens when the material of the road is different. When the wheel gets stuck in the mud, even though the engine can generate the horse power, it will not be able to move the automobile. Moreover, in order to achieve higher efficiency, the friction between the tire and the road surface becomes more important. Usually, to increase the friction, one of the conventional method is to increase the vehicle's weight. However, this conflicts with the original purpose and that is to be more efficient.
For example, when the automobile drives at high speeds, the automobile is supplied a lifting force. The wheel can not sustain enough weight any more, so it is then necessary to push the wheel down somehow. Otherwise, the wheel cannot maintain the generated driving force. Therefore, some automobiles have a front and rear spoiler to force the automobile down to maintain the proper friction with the road.
Thereafter, it is not until the tire touches to the road with enough friction that the tire produces the driving force. In order to be efficient, as long as the vehicle's weight is concerned, the lighter the better. However, in order to be efficient, as far as the friction between the vehicle and road is concerned, the heavier the better. Thus these two objectives are in total conflict.
The speed of the automobile is controls by depressing the acceleration pedal, brake pedal and changing gears using the clutch. Therefore, even though the automobile maintains a direct motion, the driver must control these devices.
Regarding deceleration, because the only contact point to the road is the tire. Braking the wheel creates the breaking friction with the road. This is the philosophy behind deceleration. The mechanism of breaking or deceleration is simply the regulation of the rotation of the wheel. The current braking system is the wheel braking mechanism. In this mechanism, each wheel has an inner disc which is encased by the pad, which expands to produce friction and slow the disc and wheel. Therefore, the area being pushed is limited, so that the breaking power is relatively small. Also, the area which the tire touches the ground is also small, usually around 150 cm2 per wheel. Thus, the braking ability is limited and usually automobiles cannot stop on demand. Therefore, automobiles have an imperfect braking system which causes traffic accidents.
Also, if the braking system is used often, the temperature of the break pad increases, then the friction coefficient of tire plummets and it will cause the fade-phenomenon. Once this phenomenon occurs, the break w ill not operate even if the break pedal is pushed excessively. Therefore, this type of breaking system has an essential defect. The major cause of this defect is based on the excessive power produced by pushing pad and is then loaded on to the small pad to try to obtain the breaking power.
The capability of the automobile is connected not only with ability of the mechanism, but also the ability of the driver. For example, according to the road law in Japan, the breaking distance is defined by each driving speed. In order to define the distance, the reaction time is taken into consideration. This reaction time is designated at 2.5 second. In this reaction time, two times are included, one is the human reaction time which is 1.5 seconds and the other is the action time which is 1.0 second.
Thus, traffic regulations and road structures are affected by the factor of such human sensory organs and reaction time. In other words, the road-automobile transportation system is greatly affected by these human factors. This indicates that the current road-automobile transportation has fundamental potential flaws.
As it is described above, because the automobile has adopted the internal combustion engine, harmful exhaust gases such as NOx, SOx and CO2 are polluting the atmosphere. Especially, trucks for logistics are the major cause of this problem. Recently, global warming, global green house effect are becoming serious problems. In Japan, more than 18% of all CO2 exhaust comes from automobile transportation, and more than 80% of CO2 from all transportation derives from the automobile transportation. Thus, CO2 exhaustion from the automobile is a significant problem. In such circumstances, electric vehicles are now under development. However, there are many hurdles to clear such as efficiency, light and a longer lasting economical battery for generating power. Because of these problems, the electric car is far from prevalence in comparison in use to the internal combustion engine automobile.
In the United States, in 1982, the Department of Energy studied the "Electric-Powered Highway" in which electrical power is supplied from the road to the vehicle. The LIM (Linear Induction Motor) is installed on the specifically designed road and the reaction plate is installed on the vehicle. The vehicle also contains the internal combustion engine to drive on general roads. When the vehicle drives onto the LIM-road, the reaction plate is pull out to obtain the driving force from the LIM. This type of vehicle is called "LIM type automobile. Cited from the book of "Handbook of Linear Motor Application", author; Hajime Yamada, Association of Industrial Research, Dec. 10, 1986, p32-p33)
This LIM type automobile is driven by clean energy because the power is generated by the electrified highway. Although it is an environmentally friendly system, it is necessary to reconstruct the regular automobile to fit on the electrified highway. This reconstruction is the car owner's responsibility. The cross section of the roadway is composed of a convex shaped road surface and the automobile is held to the convex section with rollers. Because of this road shape, it is very difficult to perform fast merging and diverging. When the automobile needs to change lanes, the convex section hinders diverging. Therefore traversing the convex section becomes absolutely necessary. Due to these disadvantages, the LIM type automobile concept, in which the driving force comes from the road, can not be realized yet.
The automobile gains it's driving force from the engine and the wheel is rotated then the tire turns and move, as described above. There are many types of road, such as asphalt paved roads, concrete paved roads and gravel roads. However, in this patent, unless otherwise specified, "road" means the road which is somehow paved. The subject vehicle drives on it.
The contact point between the road and the vehicle is the paved surface of the road and the tire of the vehicle.
General automobiles use air pressurized tires as wheels and have elasticity. The main function of the tire is to support the heavy weight of the automobile. It also suspends the automobile's body by utilizing the elasticity of rubber and contraction capability of air, in order to absorb the unevenness of the road surface. The second important function is that it transmits the driving force, wheel speed changes which accelerate and decelerate the vehicle. Another important function is the steering force which is generated by friction and elasticity to change the direction. ("Getting started mechanism of automobile" published by the Grand Prix, edited by GP Planning center, p 152, Mar. 15, 1988).
The suspension system is for connecting the vehicle body to the wheel, and it's major assignments are to absorb shock from uneven ground, to make the rode comfortable, to stabilize the driving condition, to obtain more braking ability and to be more maneuverable.
With such a mechanism, the automobile has a more advanced suspension system than the railroad with respect to noise and vibration.
In order to change the vehicle's traveling direction, the automobile steers it's wheels. The usual steering system is first comprised of a handling mechanism such as the steering wheel which the driver handles, the steering shaft which transmits the rotation power from the steering wheel to the steering gear box. The gear mechanisms in the gear box amplifies the rotation motion from the steering shaft and converts the rotating motion to a reciprocal motion. The comprised link mechanism which transmits the reciprocal motion from the gear box to the wheel in order to change the wheel angle. ("Handbook of car mechanism" published by Natsume Company, author; Motoo Aoyama, p 165, 1994).
With an automobile steering system, the human needs to drive the automobile. The steering wheel, which the human controls, controls the direction of the automobile and is necessary to transmit the angle of rotation of the steering wheel to the angle of the tire. Then the complex mechanisms of transmitting and converting becomes necessary. Because of these necessities, there are some problems. For instance: the body of the automobile becomes heavier and the transmitting and converting mechanisms become very complex.
The angle for steering the tire is usually obtained by the steering system. However, when the tire is angled by the steering system, the tire begins to slip sideways, and sideways sliding generates the sideways force to the tire. All the while, this generates friction between the road surface and the wheel. The wheel then is rolling and sliding sideways at the same time. This is how the steering force is generated. Therefore, the automobile doesn't go in the direction of the tire direction. In order to obtain the sideways force (guiding force or cornering force), sliding sideways is necessary.
Thus, for general automobiles, the driver controls the steering wheel while he watches the front of the automobile. Steering the front wheels change the direction. Consequently, the tire obtains the cornering force from the friction which is generated by the sliding force from the tire, then the automobile can turn on the road.
The guiding force (cornering force) is obtained by the steering system, suspension system, tire and friction between the tire and the road. Therefore, the conditions of the surface of the road also affects the steering and guiding forces.
Usually, the method with which the driver controls the front wheels is steering. However, another system such as the four-wheel steering system is also available.
Though the usual road is constructed from concrete or asphalt, the real conditions of the road surface is affected by the weather. When it rains, the surface of the road becomes wet, then the tire becomes slippery and this results in difficulties controlling the steering. Also, when wind blows from the side, controlling the steering wheel becomes difficult. When it is foggy, visibility of the driver becomes low, therefore, the steering conditions are affected significantly.
Therefore, the steering conditions are always affected by not only the course of the direction, but also the weather, the driver's mental conditions and capability conditions. Then, the driver must consider all of these different and changing conditions. Thus, the burden to the driver is significant and there are many opportunities for human error to step in.
Basically, automated driving can be established by the control of speed and steering. Both factors are necessary.
The method of controlling the speed of the automobile is as follows. The driver steps on the acceleration pedal to control the throttle of the air/gasoline valve carburetor to put more rotation in the engine, and steps on the clutch to convert the transition gear to control the rotation power of the wheel to control the speed. (In automatic transition systems, selecting the speed level lever, and controlling the acceleration pedal to control the speed) The other speed control is braking. Braking is controlled by stepping on the brake pedal.
Usually, this speed control is carried out by the driver. Especially on the highway, the driver pays attention to the front of the automobile so as to not tailgate the automobile ahead. To keep a safe distance between automobiles. On the other hand, the driver cannot pay attention to the rear direction as much as the front direction. The driver cannot watch the back at all times. Therefore, rear-end collisions sometimes occur.
Thus, in a usual automobile, controlling the speed contains the possibility of human error, because it depends totally on human thinking and reaction time. Sometimes, decisions cannot be made in time to prevent accidents.
Even though some automobiles are highly mobile, humans control these abilities by riding and driving in the automobile. On the other hand, as each driver has different driving skills. Different drivers judge their driving environment, and drive accordingly. Therefore, the capability of controlling the automobile is limited by the human abilities such as the senses, reaction time and response time.
To improve the above limitations in human ability, supporting measures are now being considered and are becoming available. In the automobile industries, concepts of integrated control systems have been introduced recently. Each developed technology such as 4WS, 4WD, ABS active suspension are integrated to higher levels of control to be a more sophisticated system. For example, to prepare for the ever changing circumstances, learning driver's skill to adapt optimally, there is a proposed system called "Adaptive Vehicle" (U.S. Pat. No. 4,829,434).
However, this integrated control system is only for the supporting system which assists the driver. This is an attempt to help the driver perform better. The system is not damaged for autonomous control by the automobiles with automatic steering systems which sense the driving conditions. It does changing speeds of the automobile automatically nor braking automatically. Also, the system can only provide a limited maximum speed which does not exceed usual automobile's speed. The engine is still the usual gasoline engine. Therefore, the environmental issue is not totally solved yet.
Regarding the steering system of the proposed automobile, in order to control the direction of the automobile, the usual steering system is adopted. By rotating the steering wheel, the angle of the tire is changed. Then the friction between tire and road surface is generated. This friction is converted into a sideways force on the tire, which results in a side direction change of the automobile.
By this sideways force to the tire, the sideways direction of the automobile is controlled. This steering system is completely different from the other transportation system. Therefore, in the automobile transportation system, in multi-lane roads and even in single lane roads where there are no oncoming cars, changing lanes is possible. However, driving in the opposite direction lane frequently causes traffic accidents.
In both speed control and steering control, the basic system is controlled by the judgment of the human to drive according to his judgment.
In the general automobile-road systems, as it is described above, the control performance is totally dependent upon human driving skills and the condition of the tire or surface of the road. Because the directional control is dependent upon the control of steering, the directional control is completely dependent upon the circumstances surrounding the automobile. Thus, when it is raining, the tire becomes slippery, then the diver must consider this while operating the vehicle. If the driver makes a mistake while steering, the automobile may deviate from the lane it's supposed be in.
In the general automobile-road systems, there is no mechanical fail safe system to prevent the automobile from deviation from the driving lane. All of the control of operating the automobile is totally dependent upon the driver's perceptions, skill and technique, reaction and circumstances affecting the road such as weather.
Of course some roads have guard rails or guard cables installed to prevent the automobile from intruding onto the sidewalk to protect the pedestrian's safety. However, this guard rail or cable is not for preventing the deviation from the driving lane. The center divider is the same, the center divider is to prevent the automobile's head on collisions, not for preventing the deviation from the driving lane.
After all, prevention of deviation from the driving lane is absolutely depended upon the driver's control. There is no fully automated control system which prevents the automobile's deviation from the driving lane yet.
Diverging and merging the automobile on the road from one lane to another lane occurs all the time especially on the interchange section or junction area of a highway. Also, from the general road to the highway, the automobile must merge into the highway driving lane. Even when the automobile diverges from the highway to a general road, the automobile must merge into the general road from the highway. Basically to traverse from the main roadway to sub-roadway or vice versa the automobile must diverge and or merge to the other. There are many such cases. However, in this patent, it is described only in highway cases.
In diverging and merging systems of general automobile-road system, control by the driver's steering wheel rotation changes the direction of the automobile toward the next traversing lane. From the main driving lane to the diverging ramp, or the merging ramp to the main driving lane, in the acceleration or deceleration areas, the driver controls the steering system. As a result, the automobile's diverging and merging are complete.
Therefore, when the driver wants to diverge from the highway on the interchange section, the driver must prepare to diverge. In other words, the driver must have had previously decelerated, then change lanes from the main driving lane to the diverging lane. Because the driver must decelerate and change lanes, as it is described, the capacity of the traffic is decreased around the interchange section. This is the significant problem of the existing transportation system.
Not only in the case of diverging, but also with the merging case, when the automobiles proceeds through the interchange section, the driver must observe the traffic conditions of the main driving lane of the highway while increasing the speed. The driver must find a space to fit in the main driving lane on the highway. Often, the driver cannot accelerate the automobile enough to find a space on the highway. Sometimes drivers who are on the main driving lane must decelerate their automobile to make space for the other automobile which wants to get into the main driving lane. Thus, around the diverging and merging areas there are accelerating automobiles, decelerating automobiles and lane changing automobiles. Because of such conditions, interchanges or junction area decrease their traffic capacity when compared to the straight roads which do not have interchanges and diverging or merging sections. Also, the probability of a traffic accident becomes higher in such an area.
Concerning general diverging and merging procedures on the road, because the driver must rotate the steering wheel to change the automobile's direction to diverge or merge by himself, then change from the main lane to the ramp toward the diverging or the merging lane, if the driver make a mistake of judging circumstances or steering, there is a high probability of accidents occurring in the area where with deviating from the lane is allocated to take place.
While diverging or merging on the road, such diverging or merging is completed by the driver's rotating the steering wheel. In other words, the diverging and merging is performed by the driver's steering and speed control. Thus, diverging and the merging are one of the functions of the steering system.
In the general road-automobile transportation system, in order to diverge and merge to other traffic lanes, it is necessary that the steering is controlled by the driver's rotating the steering wheel.
There is only one method available to control the steering wheel, which is that the driver must manually rotate the steering wheel by himself according to his interpretation the circumstances such as weather, condition of the road or the situation of other automobile.
According to the manual steering method, steering is controlled by the rotation of the steering wheel by the driver, and the driver observes the circumstances and around the automobile such as the situation of other automobiles and the timing needed to change the direction or lane in order to diverge or merge. Not until the driver makes a mistake controlling the steering will deviation from the driving lane not occur. However, if the driver makes a dangerous mistake controlling the steering, deviation from the lane occurs and may result in sever accident.
In the railroad system a train cannot change it's lane without switching rails itself. But general automobiles can change their lane by changing the direction progressing forward. Even passing other vehicles is possible on regular roads. However, this freedom of changing lanes is perilous, because if the driver or automobile falters steering could lead the car into an oncoming lane. This may result in ahead on collision or the driver may cut off another automobile's right of way which may also result in a sever accident.
The general automobile-road system has intrinsic problems which are explained above. Also the control of steering is totally dependent upon the skill of the driver, there are many accidents based on this transportation system. In Japan, nearly 10,000 people are killed annually by traffic accidents.
Regarding the bumper of the automobile, the current bumper can absorb some collision force. However, the bumper can absorb the force only after the collision taken place by changing the shape of the bumper. Therefore, the amount of force it can absorb is limited to a small amount. Thus, this limited absorption of a collision force is a problem.
However, there are proposed force absorbing methods; one of which is that of the air bag being installed in the automobile and before the collision occurs, the air bag is inflated to absorb some force of collision instead of direct absorption by the bumper. (Japanese Patent Application No. Tokkaihei 6-144154). However, according to this method, the air bag may inflate even in the case in which the drive may have avoid the accident. Therefore, this proposed method is difficult to use realistically. Also, even if the driver is driving perfectly, another automobile may strike this driver. The perfect driver has the possibility of being involved in many accidents. That is why they are called accidents.
In other words, during responsibility is not solely dependent your own driving skills, but also dependent on other divers too.
In Europe, the United States and Japan, these three regions, automobiles and road transportation systems, railroad and airplane transportation systems along with other transportation systems, development of the ideal transportation system has been studied and deployed intensely with intellectualization of all types of transportation systems, such as ITS (Intelligent Transport Systems). (Akio Hosaka, "Trend of development of ITS in Europe", Journal Road, Mar. Japan Road Association).
According to the European research and development project of ITS, the automatic steering system is installed on regular automobiles. Then the automobile is driven on specified roads. This system has been experimentally tested.
In the USA, the development of an automated highway system and it's field testing is mandatory under the law. (Kentaro Sakanoto, "Trend of development of ITS in the United States of America" Journal of Road, Mar. Japan Road Association, pp. 25)
So far, in the development of an automated highway system in the United States of America, there are three phases. The first phase is the preparatory phase, the second phase is the system definition phase, third phase is the operation and evaluation phase of ITS. Now it is just after the end of the first phase.
For example, on the highway, when an accident happens in front of an automobile, the automobile has a high probability of getting involved in the accident. That accident may cause a multi-collision accident. Also, in case of the road doesn't have a center divider, even if the driver keeps his proper driving procedure, the other oncoming automobile's driver might suddenly move over the lane and this results in a head-on collision.
Trains or railroad can only run on the rail. Thus, unless the train moves onto the other oncoming rail as in the automobile's case, the head-on collision will not occur.
As explained above, in the general automobile-road transportation system, even if the driver pays attention to his own driving, his safety is totally dependent on the probability of another driver's action, skill or manner. Therefore, the automobile-road transportation system has intrinsic problems.
On the other hand, recently the automated highway system has been developed. This provides that control and sensing devices are attached to the regular automobile. These allow the driver to drive automatically on the specially made road which has magnet markers installed on it.
Regarding the field tests of the automated driving system, in California, there are actual field tests which have been carried. This is called the PATH (California Partners for Advanced Transit and Highway) project. Under the PATH project, development of sensor and communication methods, experiments on driving lanes, while diverging and merging and tests of control of distances between cars and lateral distances are being undertaken.
Regarding the field testing of an automated driving system, for example, in California, there is the PATH (California Partners for Advanced Transit and Highway) project. Under the PATH project, development of sensors, communication methods, lane changing methods, diverging and merging methods, and control methods of distance between cars and lateral distance methods are being undertaken.
To further explanation detailed field testing, each car has sensors which detect the distance between cars and their relative speed. The distance between the cars is then controlled. Also, communication and information exchange between the cars by radio waves is being tested.
Concerning lateral distance between cars, at Richmond Field Station, University of California, the method of utilizing automatic steering system has been tested. The method of lateral control is that basically magnets are buried in the road surface, the magnetic sensors detect the magnetic wave to grasp the direction of the road. (Takayuki Ooba, "Topics of ITS in the United States", "Journal of road-transportation economics" January 1995, published by the Economic Research Group Incorporated Foundation).
In Europe, there have been two major projects, the first one being PROMETHEUS (Program for European Traffic with Highest Efficiency and Unprecedented Safety) project which promotes high level functioning of the automobile and the second is the DRIVE (Dedicated Road Infrastructure for Vehicle Safety in Europe) project which promotes a higher level of road-vehicle transportation.
The PROMETHEUS project was started by mainly European automobile manufacturers in 1986. The project has developed an improved safety level, efficient transportation, convenience and remedies some environmental pollution. However, it was stopped in 1994. Then the new project named PROMOTE (Program for Mobility in Transportation in Europe) was started in 1995. In the new project, not only develops vehicle technology, but also controls traffic are being researched.
In the PROMETHEUS project, control of the distance between the cars has been studied to maintain a constant distance. Automatic steering using the information from the distance sensors has been tested.
In Japan, the ARTS (Advanced Road Transportation System) project which promotes and studies a higher level of the road control has been carried out. In this project, for example, lateral control for cars has been studied.
In the ARTS project, according to the current phase of the development, provides information and warnings, and driver support while fully automated driving is assumed. In the last fully automated driving phase, the car becomes fully automated and controlled by the collected information concerning the distance in front and behind, on the sides or side barriers. This information is controlled by the sensors which are installed in the infrastructure, such as on the surface of the road and in the car. These regulate the accelerator, throttle, brake and steering wheel automatically.
As described above, in various countries, the automated driving system has been studied intensely by using radio waves, light waves, sound waves, electromagnetic waves to communicate with the road and other vehicles. However, this wireless communication method has many problems which must be solved. These include interference by wave noise which is untraceable. This will result in circumstances when the cause of a problem cannot be determined.
If an accident occurs in this fully automated driving system using the wireless method where the control system is totally dependent upon the insubstantial waves; identifying the true cause of the accident would be difficult.
More precisely, the real cause of the accident is either interference caused by wave noise, which is totally unpredictable and insubstantial, or control failure of the vehicle traffic control system. Therefore, identification of the real cause would be difficult. Also, who will take responsibility and how the responsibility will be taken would be totally indeterminable.
In the case of the fully automated driving system which is controlled by road-vehicle communication and intellectualization, because the car has the wireless devices, boundaries of responsibility of an accident become unclear. As a result, this fully automated driving system can only work in the testing phase. It will definitely not work in the real world, because it is difficult to obtain a social consensus under such conditions.
Moreover, in the automated driving system based on advanced information systems, there is no mechanical or physical fail safe mechanism or system to prevent the vehicle from deviating from the driving lane.
Problems also occur when there are accidents, system failures or even strong wind. These also affect the automatic steering of the automated vehicle. This automatically puts the driver in danger. (if the vehicle runs at high speed, it's inertia increases significantly and this will result in difficulties to avoid danger) Thus, in this system, there is always the possibility that the vehicle will deviate from it's driving lane. These problems are significant.
So long as this automated driving system has the potential to cause sever problems, it is difficult to obtain a social consensus to accept it as normal infrastructure of society.
The automated driving system has been studied and developed in many countries. However, the proposed systems has not guaranteed mechanical or physical fail safe system yet, even if the designated lane is installed for the automated driving automobile, there is still a possibility that regular car, which is not automated, may enter the designated lane because there is no physical barriers. Therefore, the lanes are basically mixed for automated and not automated automobiles. If the designated lane excludes regular automobiles, the road would become very high cast to construct.
Due to this problem, even in the automated driving lane, the automated automobile must be driven considering the other regular car's behavior. And the automated car must have all type of sensors to detect the other car's movement. Under such conditions, there is too much information to collect. This is because analysis of the surrounding conditions is too vast to process in real time. In addition, based on this enormous information, calculations regarding the driving environment such as the velocity, the direction and the position of each car must be done in a moment. Then, all of the commands to control the vehicle driving are determined and decided. The necessary information is transmitted to the steering system and the engine. Finally, each vehicle in traffic is integrated and controlled.
Generally, because all automobiles do not run on restricted guideways such as train tracks, there are intrinsic problems. These include the vast amount of information to control the vehicle's movement. Such problems also include control of an automobile with rubber tires. The unpredictability of rubber wheels is uncontrollable by computer because of constant slippage.
In order to realize the automated driving system, it is absolutely necessary to utilize the sensors, the CPU (computer), and the control devices. As a result, the cost of the installation of these devices will be passed on to the driver.
The driver is also responsible for maintenance of these devices. This means that the driver must inspect all of the devices to make sure they are functioning correctly before he uses the automated driving system.
The improvement of road, for example, with LCX (leaky coaxial cables) or inductive magnetic cables involves installation on the road surface. Maintenance of these communication cables is assumed by the road administration. However, in the long run, maintenance cost will be greater for the consumer. In effect, if the driver wants to automate his automobile, a tremendous investment is necessary.
The road management administration may be able to enforce inspection of cars before they enter the driving system. However, it is also possible that during automated driving, some electronics devices breaks down or malfunction. Whichever the case, as long as the automated driving devices are installed on the automobile, the responsibility of the automated driving belongs to the driver. The more advanced or complicated systems, the more important is the maintenance of those sophisticated devices. Such advanced and complicated automobiles may not be accepted by the consumer, because the more advanced and complicated the automobile becomes, the more the burden to the consumer. Not only will the initial price more expensive, but also maintenance will carry a high price tag.
The semiconductor chips utilized in electronic controllers, can be affected by electromagnetism, as a result, malfunctions occur. For example, in the airplanes, passengers are regulated and asked not to use any electronic devices such as radios, cellular-phones and PC's, etc. when the airplane takes off and lands.
Semiconductors do not tolerate high temperatures above 40 degrees C. They malfunction when this temperature is exceeded. When the automobile is exposed to direct sun light, the temperature may reach 50 or 60 degrees C. Also, the automobile propulsion section, such as the engine area generates a much higher temperature. Therefore, even if the automobile is inspected at the entrance of the automated driving road, and no problem is found, this will not guarantee a malfunction of the electronic devices. Thus, when the automated driving system, which relies completely on automatization, experiences an electronic malfunction, it is difficult to guarantee total safety. System failure caused by these situations at high speeds is extremely dangerous for who use the system. Unlike system failure at low speeds, the driver does not have enough time to secure manual control of the automobile. This is a basic problem with the fully automated system.
For example, while the automobile is in the traffic congestion, the automated driving system is carried out more easily during low speed. Also, even if some electronics malfunction occurs, manual measures can be tackled. However, if the same problem occurs during high speed, it will result in sever traffic accident.
The electronics devices can support or help automobile control. However, there is a limitation on electronics technology for letting it control driving completely. Driving control affects the passenger's life.
It is highly possible of fully automated driving system which is supported by the intellectualization of information using electronics devises. However, there is a significant problem in driver's "anxiety" (which anxiety lies on insecurity in a fully automated automobile is something to be considered). This insecurity is mainly caused by fully automated driving system which is dependent only on invisible "wireless" electronic control system on both road and vehicles. The public's consent is necessary for full automation. But obtaining public consent seems to be difficult based on the fully automated driving system. For example, if the automated driving vehicle accidentally deviates from the lane by device's malfunction, no driver can react in less than a second. Because the malfunction could occur in very short period of time. The insecurity is caused by non-existence of physical and mechanical fail safe mechanism in the fully automated driving system.
As mentioned above, there are many problems in the automated driving system. In this system, the driver grasps the steering wheel to control the lateral direction of the automobile. This includes merging and diverging from lane to lane by controlling the steering wheel. Such manual methods have the potential for making mistakes.
The lateral control by steering system of the automobile provides smooth traveling. This steering system is better than the other lateral guiding system such as railroad, monorail and cable car transportation system. However, from the safety point of view, this lateral control by steering system does not guarantee driving safety. Because the lateral movement is free and is not guided mechanically.
Even if the automated driving system is realized, the automobile itself is still powered by the internal combustion engine. This is powered by burning gasoline. Thus, this automatization will not remedy environmental pollution perfectly. Also, the maximum speed of the vehicle will not exceed the maximum speed of automobile. As a result, it will not provide fast transportation such as the Bullet Train System. For future transportation, faster transportation development is required for human and commercial mobility.
As explained above, there are many problems related to the automated driving system using electronics devices.
Now, the objectives regarding the development of roads for the automated automobile driving system are as follows.
On general roads, passenger automobiles and trucks travel together. Also, they can use any lane. Most general roads are designed as heavy duty in order to meet the needs for the heaviest truck. Therefore, from a different point of view, most of the road is unnecessarily over designed, especially paved structures and bridge structures.
For example, the general bridge floor is designed to meet with the weight of the heaviest truck that uses any lane on the bridge. If the truck is restricted to some particular driving lane, the other lane is not necessarily designed for heavy trucks. This lane is reserved for passenger vehicles, which are usually lighter than trucks. Therefore, such restricted driving lanes let the bridge be designed lighter and more economic.
In general bridge design, passenger vehicle bridges are much wider than bridges designed for only trains.
Furthermore, on the bridge, traffic is always intermixed with passenger vehicle and trucks on the same regular road. The strength of the structure of the bridge is usually designed based on the heavy automobile such as heavy duty trucks.
In designing a bridge, any driving lane of a bridge floor is designed to allow any type of vehicle from light to heavy. In order to accommodate to the large moment force from the heavy duty vehicle, the girder structure becomes bigger and heavier. This designing issue causes several problems. For example, to obtain a large space or a longer cross-section, the longer span length must be sacrificed.
In order to pave the road, currently asphalt or concrete is used. However, asphalt is an elastic material, it makes a wheel track easily. Also, the concrete needs seams to install, and has a technology to have cracks. Therefore, to maintain road surface cost becomes greater.
Why not use steel for the road pavement? It is too heavy to use for the road, it must cover the whole road surface because the wheel running track is not fixed. Also, when it gets wet with rain water, the coefficient factor of friction between road surface and wheel becomes small and this causes a slippery surface and drainage is a problem.
Recently, an energy-saving road has been promoted, such as solar-cell panels, heat panels and heat pumps have been started to install on the side walls of the road. Sound-proofed walls or sunshade roof have also been used. Usually, the road surface takes the widest area in road section, but this surface is used for the runway of the vehicle, this has not been used for energy-saving purposes.
The leaky coaxial cable (LCX) for the road communication system has less quality unless the antenna and overhead line directly faces the direction of the moving vehicle. If it is installed on the side of the shoulder of the road, sometimes other vehicles between the vehicles and the side shoulder hinders transmission, and the quality of the communication decreases. In the current system architecture of the road-automobile system, the automobile doesn't run on a restricted lane, but anywhere on the road. Thus, the problem described above becomes a real problem. To solve this type of problems, the place to install the LCX becomes the main issue.
The laser beam reflection detecting system is utilized to measure the longitudinal and lateral distance between the vehicles. This method is very accurate. However, there are no reflecting materials without interruption on general roads, and there are no places to install such reflecting devices.
In the highway system, the intersection is designed for crossing with an overpass or underpass to avoid vehicles running into each other and to maintain traffic capacity and safety, but this system is costly to build.
In tunnel, ventilation is necessary because of the vehicles exhaust gasses, thus the area of cross section becomes wider.
Also, in the general highway system, the road cannot control the movement of each vehicle. Therefore, if there are vehicles which way collide with one another, there is no method to make the distance longer between the vehicles, or to stop the vehicles. It means that the current road system doesn't have the ability to control the vehicle's movement actively.
The next issue is related to the railroad. In the railroad system, the guide for traveling is performed by steel wheels and railroad. Then, the traveling of steel is restricted physically and mechanically. Therefore, the rail car does not de-rail unless a significant accident happens such as large scale earthquake or natural disaster or human error.
Based on the facts which are explained above, a rail car transportation system is much safer than the road automobile transportation system.
Most of the rail car system can be powered by the electric motor, therefore this system is more environmentally friendly than the road automobile system.
However, this railroad car system contains a demerit of individuality and free accessing. Because the car can drive only on the rail which is limited by the railroad network. Thus, the railroad car is used for traveling from fixed point to fixed point.
In this electric motor driven railroad car system, the propulsion force is gained by the rotation of the steel wheel on the rail. Actually, from the friction between the steel wheel and the steel rail. This is called "adhesion propulsion method". In this mechanism, the maximum speed is approximately 330 km/lh. (an France, TGV recorded 515.3 km/h in 1990 as the worlds highest speed for a railroad, but this has been recorded under ideal conditions not under normal operation conditions.) In the railroad system, there is a potential possibility of an accident when a natural disaster occurs such as an earthquake or strong wind, etc. However, the wheel is restricted to the guide-rail, so that the lateral movement is regulated by the rail. Thus, the probability of accidents of lateral crashing is much less than the road-automobile system, even if the car loses control. The Shinkansen in Japan, which is the bullet train system, since service started in 1964, a regular diagram has been set at the highest speed of 210 km/h. So far, there have been no accidents resulting in injury or death (Currently, "Nozomi" is traveling at 270 km/h as it's highest speed).
Basically, the railroad transportation system is safe. But, the metallic noise, and sound problems exist. This is because it is driven by the steel wheel and the steel rail, which are rigid bodies, to obtain the propulsion friction, also to support the car.
This system adopted steel wheels and steel rails not only to support the car, but also to guide the direction of the car. The flange type wheel is utilized to travel on the rail. The internal ring flange of the wheel pushes out the rail and expands the distance between the rails. This function makes a more reliable guiding toward the rail by receiving a lateral restriction force.
In order to guide the car, a 1/20 grading of internal flange is put on the surface which contacts with the rail surface. (The Shinkansen system adopts 1/40 grading) Due to this lateral guiding system, especially in straight rail lines, the force from the both right and left rails centralize the position of the car. In the curb section, the wheel is shifted to the outer direction by centrifugal force. This results in smooth curbing. ("An illustrated references book of railroad car", written by Kazuo Ihara, Sep. 10, 1987, published by Grand Prix Publishing Co., page 225).
Therefore, the wheel receive both supporting and lateral force from the rail. In order to sustain these loads, the wheel and the rail must be made from steel. In general, a unit rolled wheel is utilized.
In the general railroad system, supporting and guiding are completed by adopting steel wheels and steel rails. The accuracy of installing the rail affects directly to the ride the feel, the noise and the vibration. Thus, continuous maintenance of the rail conditions is absolutely necessary. But this maintenance cost is high and it is tedious work.
Also, when the rail car needs to merge or diverge, the rail which is always supporting and guiding the wheel, must switch the whole section of railroad from one track to another.
In the turnout of the railroad, it is comprised of the point, the crossing point the leading part and the gird part. It is then switched by the transferring tongue rail mechanically.
The speed of merging and diverging depends on the speed of the mechanical switching points. Thus, in the railroad system, it is difficult to merge and diverge in a short period of time.
Also, when the train changes its driving lane, a crossing over section is needed between the lanes. Often, the scissors crossing section between the lanes is used. It is usually comprised of four turnouts, and a diamond crossing section and this forms an "X" shape. These mechanical mechanisms are complicated, therefore, it takes a long time to switch over from one lane to another.
In addition, the railroad transportation system is not individually driven, and it is not a random transportation. Basically, it is mass a transportation system. This is really a demerit of the railroad, because it cannot meet with the individual, but is attached to a plurality of cars to make one train.
Usually, the train is composed of many cars, it then becomes heavy as a whole train. Thus, the railroad structure usually requires heavy and strong structure to endure the heavy load. Also, the bridge for the railroad is designed based on the heavy weight of the train system.
In the guide rail transportation system, which is categorized as a unique form of railroad, in order to decrease noise and vibration from the steel wheel and steel rail, a rubber wheel support car "I" shaped steel guiding rail, which is installed in the ditch which is located in the center of the driving lane, is installed. The other method is the reversed "T" shaped rail which is installed in the center of ditch. Guiding or the side wall is pushed out by the wheel towards the outside. (Both of them are called center guided systems). The side wall is made inside of the outside wall of the driving lane. And the lateral guiding wheel is pushes the side wall to obtain the guiding force for the car.
The method of the reversed "T" shape rail is set in the center of the guideway. The guiding wheels hold the rail. This has been constructed in Sapporo in Japan as the city subway system. This system makes less noise and vibration. ("Civil Engineering Handbook II", Japan Society of Civil Engineers, The thirty sixth edition, page 1582).
There was a transportation system which is comprised of the ditch which is installed at the center of the driving way, and the guiding wheel is introduced to contact with the side wall of the ditch. This system has been developed as CVS (Computer Vehicle System) in 1970 by Japan Society for the Promotion of Machine Industry. ("CVS technical Report", Japan Society for The Promotion of Machine Industry, published in March, 1973).
The double sided guidance system in which the side wall is installed and on which the guide wheel runs, has been in use as Kobe's new transit system named "Port Liner", for example.
These new transit systems utilized the guide wheel system. The control is performed by the guide wheel and the rail or the wall. The point is that the guide wheel is always running on these rails or walls with direct contact. It is not steered by the wheel like a regular automobile. The guide wheel guides the vehicle with rolling on the guide rail or wall. In other words, the angle of the front wheel guides the direction of the vehicle.
Thus, the guide wheel easily reduces the noise from the guide rail or wall. Vibration usually becomes the significant issue.
In "U" shaped guideway transit system, which is sometime called the "both-side" guidance system, the vehicle is driven in the guideway as the guide wheel is protruding from under the vehicle to push out to the side walls to obtain a sustaining and guiding force to the vehicle. This type transportation is in use in the Osaka Nanko Port Town line. According to this system, the suspension system is installed between guide wheel and the support of the vehicle body.
Also, the installation of guiding wheels is necessary. Thus, it becomes an enormous machine, and not only the ditch is necessary, but also it requires the guidance rail. In the "U" shaped guideway, the transit vehicles are dipped into the guideway, so that in case of an emergency, it is very difficult to evacuate the vehicle from the guideway. (It is almost impossible for the vehicle evacuate using the other guideway, because the guideway is restrained).
Therefore, the transportation system which needs to operate many vehicles on the guideway, the "U" shaped guideway has potential difficulties to accommodate emergency case. It is also difficult to remove the malfunctioned vehicle from the guideway, because the vehicle is dipped into the guideway.
Moreover, such a "U" shape guideway has much less compatibility with other guideways. If one lane malfunctions and many vehicles are stuck, those vehicles face difficulty to change their driving lane. This is because the guideway itself becomes an obstacle for the vehicles to move over.
There are many methods for diverging and merging procedures and rail changing methods. The flexible guidance plate, which operates on the diverging section connected with the diverging wheel is installed and the diverging guidance wheel is gripped in the ditch. The up-down guidance rail method: the vehicle is guided by the straight flexible guidance rail which is controlled up and down next to each other. The horizontal rotary guidance girder method: the wheel guidance girder rotates to the diverging lane. The tongue rail method: the edge of the tongue rail is switched. ("Figure book railroad Engineering", written by Kozo Amano, Yasuhiro Maeno, Toshihide Miwa, Maruzen Co., LTD., Published on Apr. 30, 1992, P. 264-268.) All of the above need a mechanical ground machine. They diverge perfectly but can not accommodate many vehicles at one time. These are not quick enough for the vehicles which have only a short distance between them.
Regarding the CVS which was mentioned above, it requires much maintenance. The guiding wheel tire always contacts the guidance rail, which is installed in the center of the ditch. Due to the guiding system, either guiding wheel tire is always pushed to the guidance rail.
These new transit systems do not realize the individual accessibility randomly. They do not accommodate automobiles on the road and they don't remain compatibility with current road-automobile transportation systems. Thus, these systems are in use only in limited areas such as in large cities.
There are several inter modal transportation system other than road system such as the piggy-back system which carries trucks on trailers directly. In this system, the consignee can save some transportation cost by doing direct transportation which has the ability to extract the automobile's character by utilizing the railroad's designated transportation line.
("Handbook-2, civil engineering" published on Nov. 18, 1989, article: railroad and guideway, page 1545).
However, these are not the systems which carry automobiles, or trucks one by one. There are several demerits with this system. One is the schedule is restricted by the diagram of the train. They must stop at the station even though it is not the destination. It loses the defining character of individuality of the automobile. There is no random accessibility. Therefore, these systems are in use in limited areas such as in long-distance transportation, tunnels etc.
There is another transportation system called the "Car-Train" system as an inter modal transportation system of automobiles and railroads. For example, the "Eurotunnel" which connects the Dover-straight between England and France. The train carries many automobiles, and those are contained in the cargo. There is no car fixing apparatus to the floor. Each automobile is just fixed to the floor by only the hand brake. This is just like parking in a train. This is because the automobile is not exposed to the outside directly, but is housed in the train car. If the automobile is carried by the vehicle singularly, and it is not housed, the automobile must be fixed on the floor firmly. The "Euro-Tunnel" car-train system can accommodate many automobiles carried per car. Thus, the individuality of the automobile is non-existent.
As explained above, concerning the usual piggy back system , the car train system is the system which carries many automobiles at one time. Therefore, these systems inherit the drawbacks of train transportation because of no capability with individual transportation as with the automobile, which boasts a quick diverging and merging system.
There exists a linear motor propulsion transportation system which doesn't require adhesives between the wheel and rail.
A magnetically levitated railroad system with superconductivity was developed by Japan Railroad Inc. This is one of the linear motor systems. It adopts the LSM (linear synchronous motor) utilizing superconductivity magnets as propulsion. However, it is difficult to control because the magnetic poles must be synchronized. Also, only one train can run per electric substation. Thus, in order to operate, many substations must be constructed. Substation to substation experiments have yet to be completed.
The Transrapid system in Germany uses the magnetically levitated train system under normal temperatures and a linear synchronous motor. The levitation is performed by the mechanism of absorption power which is generated by the electromagnet that is installed under the vehicle opposite the top rail which is installed on the guideway on the ground. This basic mechanism is nearly the same as that of the HSST. The difference between these systems is the mechanism guiding the vehicle. Transrapid adopted the separate side electromagnet on both sides of the vehicle, but HSST's guiding electromagnet is integrated into the levitation electromagnet.
With the HSST system in Japan, the guiding force is obtained by the electromagnet This is the same magnet with generates the levitation power. Because support of the vehicle's body is obtained by magnetic levitation, the rail and wheel are not necessary. This provides for less noise and smoother rides for the passenger.
In this system, the LSM (linear synchronous motor) is adopted as the propulsion force. Generally, in a system which uses electromagnets to obtain guiding force, it is necessary to reduce the vehicle's weight and inertia as much as possible. When this electromagnetic guidance is performed, the ride becomes smoother, the noise and vibrations can be diminished, because no wheels or rollers are used.
However, in case of utilizing the HSST method for heavy duty transportation systems which deal with trucks, container and freight logistics, the weight and inertia increase. Thus, generating the power of the levitation and guidance at the same time becomes difficult.
HSST is a train. Therefore, it's longitudinal length is long at approximately 8.5 meters. The support body or the levitation and guidance module is approximately 2.5 meters long, one car consists of three modules.
Because the longitudinal length of the train and module is great, the mechanism to accommodate the curved section of the guidance track is a complicated link.
In the HSST system, the cross section of the vehicle structure straddles over the center guideway. So that when the vehicle needs to diverge or merge, the switching section becomes as the monorail car system. The monorail traverses the whole section of merging and diverging section. ("Technology of magnetically levitated train system", written by Eisuke Syoda et al, Aum Co. LTD., Sep. 25, 1992, page 157).
Thus, for the transportation system which accommodates heavy traffic, accomplishes quick diverging, merging and maintains the individuality of each vehicle, any of the urgent magnetic levitation train systems such as HSST or Transrapid cannot be applied.
The HSST or Transrapid magnetic levitation systems have not been developed to transport individual vehicles individually. These systems are, in effect modified train systems. When one considers the compatibility these systems maintain between the vehicle and the road, they contribute little to individual vehicle transportation. HSST or Transrapid cannot provide an individual transportation system. They are just same system as regular train system, from the compatibility point of view. Therefore, their contribution to the transportation system is not great.
Also, in the HSST and Transrapid systems, in the case of the absorption force that is generated from the LIM (linear induction motor) which is used to obtain the propulsion force; the magnetic levitation force is in the complete opposite direction. So, the levitation force is reduced. This is another drawback of the HSST and Transrapid systems.
Moreover, in HSST, when the car needs to reduce it's speed, the LIM is utilized. However, emergencies there is separate system and device that grasps the reversed "U" shaped rail to brake using hydraulics. ("Technology of magnetically levitated train system", written by Eisuke Syoda et al, Aum Co. LTD., Sep. 25, 1992, page 157).
In this type of method, the shoe of the brake straddles the reversed "U" shape mechanism. Thus, the lateral movement of the vehicle is restricted. This restriction makes diverging or merging impossible unless the whole guideway is traversed.
With the linear motor system, the most important condition for obtaining an efficient propulsion force, is controlling the gap length. This is the case whether it is the linear induction method or the linear synchronous method.
The M-Bahn system in Germany adopts a permanent magnet to levitate the car. When the number of passengers increases the system lengthen the gap. The mechanical link system then minimizes the gap length to increase the absorption force. Also, linear synchronous motors are installed on the guideway surface and the permanent magnet is installed on the bottom of the car. Then, the propulsion force is obtained by controlling the cycle frequency of the linear synchronous motor. ("Illustrated Book of Railroad Technology", written by Kozo Amano, Yasuhiro Maeda, Toshihide Miwa, Maruzen Publishing Co. LTD., Apr. 30, 1992, Page 282).
This method depends on the mechanical link system. The control of the gap is not sufficiently accurate. Therefore, a complete non-contact system is not possible using these methods.
The linear motor driven car and is supported by steel wheels, the reaction plate is installed on the ground side. The primary coil plate is installed on the side of the car. It is important to keep the minimum gap length less than 10 mm. However, in this system, the car is supported by a rigid structure. Therefore, a mechanism gap length system is adopted.
The gap length is controlled by a rigid supporting structure. Therefore, the wheel and guide rail is made from steel. As a result of adopting a rigid structure, the drawback of railroad system are inherited in this system. Also, the position of the guideway and reaction plate must be fixed accurately. Thus, the cost of construction of the guideway becomes significant.
There is another type of carrying system in which the linear induction plate is installed not on the car, but on the ground. For example, the carrying system is installed on the automobile in the automobile manufacturing facility. In this system, the primary magnet coil plate is installed on the ground side. The reaction plate is installed on the carrying pallet without any electronic control devices. However, even in this system, the gap length is kept by the rigid supporting structure. Therefore, if it is applied to the transportation system, fast diverging and merging would not be possible. This system also inherits the drawbacks of the railroad system.
In linear motor system, the higher the temperature, the less efficient the system. Thus, there is no actual in use the primary magnet coil plate installed on the ground side.
There are other transportation systems incorporate a vehicle traveling on a guideway. When the vehicle is on a regular road, the vehicle travels as regular automobile. There are two major ideas, one is "Dual Mode Bus" (Illustrated book of railroad technology", written by Kozo Amano, Yasuhiro Maeda, Toshihide Miwa, Maruzen Publishing Co. LTD.), the other is "Dual Mode Truck" (Journal of Road Traffic Economics, published by Japan Society of Economy Research, October, 1994, page 35) which has been developed in Japan. In these systems, it is necessary that the vehicle attach itself to the lateral control guidance roller and the power generator. This system requires specialized equipment Therefore, for the user, the cost will be high. Thus, the Dual Mode System (DMS) has an intrinsic problem from the view point of social acceptability and feasibility. The DMS has been studied, developed and investigated. However, it is not in use until June, 1995.
This research has continued. However, regarding the subsystems such as providing electricity, the non-contact electricity supply line has not been developed yet. The contact method needs more maintenance than the non-contact method.
The fully automated driving system has also been considered. However, the equipment for automation must be installed in and the responsibility boundary become uncertain.
There is an another transportation system called "Palleted Automated Transportation system (PAT)" , which maintains it's individuality using the automobile carrying pallet, and it has been patented in 1972 in the United States of America ("Electric Guideway Transportation System", U.S. Pat. No. 3,673,966).
In this PAT system, with the individuality of the automobile, the system is driven by electricity, thus it is more environmentally friendly. However, the guideway has lateral side walls on which the rack is installed, and the pinion is installed on the side of the pallet, it is then driven by using a synchronous motor. The basic guiding system is the side wall method. Therefore, the drawbacks that the "U" shape guiding system has exist with this system, because the basic design of the guideway is almost same. Also, the rack and pinion method is adopted. Thus, mechanical vibration may occur, and it is uncomfortable to ride on. As a result, it has not been in actual use.
There is an another transportation system using the similar pallet transportation system, which actually utilizes different diverging and merging systems using the electromagnetic method, and a propulsion system using linear motor. This system has been applied as an invention in Japan by an innovator of this patent application, named "Cyber Highway System", as Published Japanese Patent Application No. 2-175463. In this "Cyber Highway System", the automobile, which is carried by the pallet, doesn't require any remodeling work. The pallet carries the individual automobile, then moves on the designated guideway. Thus, it can retain each automobile's individuality. Also, driving is controlled by the road side (guideway), and fully automated driving can be done. In addition to this, because the linear motor system is adopted as the propulsion force, much higher speed can be expected, and cleaner automobile transportation is possible. Condensed traffic can be performed because fully automated transportation is possible. Thus, the traffic capacity per lane increases more than 10 times.
However, in the specialized guideway, the guiding system is basically the "U" shape and the pallet has guidance wheels. The pallet has no steering function. Therefore, smooth guiding cannot be expected. There are still many problems which occur from the "U" shape guideway to be solved. Also, the "U" shape guideway has significantly high side walls. Thus, sight from the automobile is hindered, and it lacks an open feeling. For the passenger, the amusement level will be less than the regular highway system.
In the case of the "U" shaped guideway of the "Cyber Highway System", the vehicle moves on the guideway and must have guiding wheels both on the right and left side of the vehicle. Because of this, the design of the vehicle is limited especially from the aerodynamic point of view.
Moreover, because it adopts a linear synchronous motor using superconductivity electromagnetic forces as the propulsion power, the unit of magnet cost must be high. In this system, conventional force such as the linear induction motor may not be installed due to the much longer gap length. (In the case of the "Cyber Highway System" invention, the magnetic field is obtained by the electromagnet which is installed on the pallet vehicle, and a direct current motor is used. However, it is necessary to install the electricity supplying cable. Thus, the excess cost for electricity is needed). Also, it adopts a linear synchronous motor. Therefore, the control of the motor is not so easy. There is the remaining problem that the realization of the linear propulsion system is difficult.
In this "Cyber Highway System", electromagnetic force is utilized for diverging and merging. When the vehicle needs to shift to one direction, the electromagnetic force is generated laterally to diverge or merge. This method improves the speed of diverging or merging much more than the whole guideway traversing method, which is used for the "U" shaped guideway.
However, if the lateral electromagnetic control system fails, there is no other way to control the movement of the vehicle. In that case, the vehicle may crash into the side wall of the guideway, because when the vehicle loses it's control, the range of the vehicle's movement is w ide. Also, the vehicle is driving at high speed, so that the carried automobile has no time to escape. Thus, the automobile may crash at the same time.
According to the method of this diverging system, the diverging operation is performed only by the electromagnetic force. Therefore, if the vehicle begins to lose it's control, the leeway of the movement of vehicle is wide. This means that there is no method to prevent the vehicle's deviation at the begging stage. Therefore, there is a high probability of crashing against the side wall of diverging island with a large amount of inertia.
Furthermore, in this "Cyber Highway System", method of fixing the automobile is merely holding the automobile from the horizontal directions not pushing down the tires. Therefore, the suspension system of automobile is inactivated. Thus, the vibration and rattling from the vehicle cannot be absorbed, and it results in an uncomfortable feeling for the passenger. This implies that it is necessary to install some suspension system to the vehicle. It then becomes a more complicated structure, and the thickness of the pallet vehicle increases. The thicker the pallet vehicle becomes, the more space necessary for the pallet vehicle parking lot, creating higher costs for building this system.
Concerning the example shown in figure (FIGS. 7 and 7-B), the automobile is surrounded by part of the pallet vehicle. In this method, the automobile will not come out from the pallet vehicle. However, the tires of the automobile are not pushed down to the floor. Thus, the automobile's suspension system is inactivated, and this results in uncomfortable riding. Also, the size of the pallet vehicle increases, so that more space is necessary for the pallet vehicle stockyard at the mode-interchange, thus causing higher costs for building this system.
Also, in the example method (FIG. 7), the automobile's tires are not fixed to the pallet vehicle floor firmly, this may cause the automobile to move from the pallet vehicle when the vehicle accelerates quickly or on hairpin curbs.
In high speed pallet vehicle transportation systems, the pallet vehicle must hold the automobile tightly especially when the vehicle moves or stops suddenly. However, according to the fixing system which the above reference cited, fixing is completed by part of the body or the airbag. Thus, does not guarantee perfect fixing, and accidents may happen.
Also, this system has a limited communication system. Thus, the driver or passenger has a difficulty to communicating to the road and pallet vehicle system.
Generally, in summer, an air conditioning system is necessary inside the car. But according to the "Cyber Highway System", the automobile cannot turn on the air conditioner unless its engine is idling on the pallet vehicle. The "Cyber Highway System" has not considered this point of view.
In the "Cyber Highway System", the main target of carrying is passenger cars, not trucks or buses. It is not a written detail of how to carry these large sized automobiles such as trucks or buses.
Also, it is not clearly written how to carry container freight for trucks. However, containerization is increasing now, due to increasing international container freight distribution.
There is a system which adopts the electromagnet force to diverge and merge. This has been presented as a Japanese patent application 51-6404. In this method, diverging is performed by the propulsion force which is generated by the linear motor as is aforementioned. However, this system has adopted the "U" shaped guideway. Thus, there is still a possibility of an accident such as crashing to the diverging island. This type of accident may cause more sever damage than in the normal transportation system.
In the aforementioned Japanese patent application, a linear motor diverging system can be applied to the railway also. But, when the vehicle on the rail transfers from the rail to another rail, there should be a gap length must be longer than the thickness of the outer flange wheel. Therefore, there is always a disruption between the rail, and this results in a big difference in grade. At the point of the gap, there are significant problems: vibrations and rattling, if only the electromagnet force is utilized to divert (egress).
In the conveyance field, not in transportation system, there is the LIM type X-Y actuator system which is comprised of the X direction winding generating the X direction propulsion magnetic field, and the Y direction winding generating the Y direction propulsion magnetic field. ("Handbook of linear motor application", written by Hajime Yamada, Japan, published by Industrial Research Association).
In this actuator system, it is possible to have non-contacting diverging (egress) by using electromagnetic control while arranging the balance of forces both the X-Y directions.
The basic mechanism of the aforementioned diverging system is electronic switching. This makes possible quick diverging. However, there are several problems, as follows.
One is that the diverging force totally depends on the magnet. Therefore, in the case of the large sized transportation system such as an automobile carrying system, it requires a large amount of power. Therefore, in case it needs much more power, if the electric failure or malfunction of the controller occurs, diverging is not completed. This is the most different aspect in the mechanical diverging system.
In the "Cyber Highway System", the electronically controlled air brake system is proposed as a substitute for the linear motor brake system. But the basic mechanism of braking is the same as the wheel braking system. Thus, the braking force is still limited.
The above mentioned problems are propulsion, supporting, guidance, steering, lane deviation methods, diverging and merging methods, structure of the road/guideway, vehicle structure and the traffic issue such as passing in current transportation when the vehicle is traveled on the system. This invention is proposed to solve all of these issues and problems.
In the vehicle traveling transportation system, the primary objectives of the invention are to maintain full compatibility with the regular road-automobile transportation system, to network with the regular road-automobile transportation system, not to burden to the automobile's owner with altering any remodeling of the automobile, to maintain full individuality of the automobile, to make the passenger or driver convey driving demands or destination demands for container freight, to ease driving itself for the driver while introducing the automated driving system, to operate at higher speeds, to be more comfortable, to be safer, to have smoother traveling, to have less noise and rattling, to be more environmentally friendly, to increase more traffic per lane and to reduce the cost for land acquisition and maintenance.
The following paragraph, details each subject in order to accomplish the primary objectives as they are explained above.
The second objective is to obtain an automated guided transportation system which automatically guides the traveling the vehicle which travels on the transportation system. It travels with less noise and rattling. It has a smooth suspension system which supports the vehicle for it's traveling and it travels on the system automatically based on the guidance information.
The third objective is that when the vehicle to happens to deviate from the lane caused by some malfunction in the vehicle automated guidance system, or by wind or rain related slipping the vehicle has a prevention system not to deviate from the driving lane.
The fourth objective is that in the case of utilizing the linear motor as the propulsion force, the vehicle has a linear motor system which has the ability to control the gap length, to have an enough power for the propulsion force even though the superconductivity magnet is not used, to control each individual vehicle's traveling, and can travel a long distance at high speeds. Also, the other issue is to provide the system with remedies to the environmental pollution problem and to prevent air pollution.
The fifth objective is to obtain a system which has the capability to diverge and merge quickly, smoothly and safely.
The sixth objective is to obtain an interchange system which has the capability to change modes when an automobile or freight container needs to be loaded or unloaded from the pallet vehicle automatically.
The seventh objective is to obtain a non-contacting electricity collecting system which has the capability to minimize the gap length between the electricity providing cable and pantagraph, more efficiently.
The eighth objective is to obtain a brake system which doesn't affect fading like normal automobile brakes and has the capability to stop effectively and doesn't allow lateral sliding.
The ninth objective is to obtain a detector system for longitudinal or lateral distance sensing of the vehicle with high accuracy, security and swiftness.
The tenth objective is to obtain a level intersection system which can provide accessibility toward any direction on the guideway without deceleration.
The eleventh objective is to obtain an intelligent pallet vehicle which loads and unloads automobiles or freight containers by fixing or release from the floor of the vehicle. Also, the vehicle has the ability to levitate when it carries light automobiles by electromagnetic force, and can make possible quick diverging and merging. The vehicle is to be lighter for reducing the loading force to the ground by utilizing the aerodynamic body shape, or magnetic levitation. Introducing the sliding system to the vehicle makes for a more flexible support system. Also, the flexible pallet vehicle can accommodate any type of freight container to be loaded.
The twelfth objective is to obtain a road structure which can reduce maintenance costs and requirements, and can drain easily.
The thirteenth objective is to obtain an emergency traffic shut down system from the road side in case of accidents, or weather problems.
The fourteenth objective is to obtain a system which can greatly decrease the severity of an accident when vehicles collide.
The fifteenth objective is to obtain an integrated fail safe system which has the flexibility to accommodate any situation and is able to minimize the affects if an accident or emergency occurs such as an earthquake or fire. Also, the system needs compatibility so that vehicles can move to a new lane in case of these emergency occurs.
The sixteenth objective is to obtain a system which makes it possible for a faster vehicle to pass a slower vehicle quickly and safely.